Mast Cells and Anandamide – Inflammation, Fibrosis and Growth

What Are Mast Cells?

Mast cells are made in bone marrow but are found all over the body, including the nervous system, connective tissues, and mucosal cells. At the time this paper was written, not much was known about how they work or were activated. The endocannabinoids anandamide (AEA) and palmitoylethanolamide (PEA) are similar to THC, the psychoactive chemical in cannabis because they bind to the same receptors, CB1 and CB2 receptors (CB1 mostly).

Mast cells had recently been discovered to express CB2 receptors (they were found on the surface of the mast cells), leading scientists to think that the endocannabinoid system, which contains the CB receptors, would be a good place to start looking for a way to interact with them.

Mast cells are involved in the body’s inflammatory response, lymphoma, mucous production, fibrosis, growth, and other vital processes. This study was designed to establish how the ECS was involved in any of these processes. The results were promising and confusing. A part of how HMC-1 mast cells transport and process anandamide was elucidated, along with the discovery of a FAAH, an enzyme that degrades anandamide, in the mast cells.

This is curious because human mast cells do not express endocannabinoid receptors on their surfaces. Why and how they absorb and respond to anandamide is still unclear.

The ECS in Mast Cells Is Explored

Mast cells are relatively recently discovered cells that have emerged to play vital roles in many different processes. It had been found that mast cells took up the endocannabinoid anandamide, which was curious because human mast cells are known not to have any endocannabinoid receptors on their surface. There was more going on than was immediately apparent.

This study discovered an anandamide transporter, which took anandamide into mast cells, where it is hydrolyzed by an enzyme called 5-lypoxygense. The authors are not certain as to why they do this, but the most likely hypothesis is that it is one part of an inflammation regulatory system.

Anandamide reduces inflammatory responses, a chemical called NO increases them. Through the action of FAAH, which had not been known in mast cells before, it is proposed that the two chemicals are used to balance out the mast cell’s role in inflammation.

Mast Cells Are Important ECS Regulators

It seems like mast cells are important in regulating the endocannabinoid system, which has a large role in the way the body responds to attack, infection, and trauma, as well as many other important processes. The interaction is two-way. AEA and PEA do not downregulate human mast cell activation, but they do activate other parts of the inflammatory system.

The authors conclude that mast cells contribute to the regulation of the peripheral endocannabinoid system and therefore processes like inflammation, neuroimmune reactions, and vascular tone. These are all processes that are the causes or are affected by serious diseases, especially inflammation. Knowing how mast cells can be manipulated opens them up for therapies for many different conditions.

This very technical paper is the first to describe in part the way that the endocannabinoid system is regulated in part by mast cells. There are serious medical applications of this knowledge.

Registered with the British Psychological Society, breaking the taboo on mental health issues is one of the driving forces in Jonathan's life. His background in biomedicine gives him additional understanding of the factors that work together to influence the human condition.